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bioRxiv · 10.1101/2025.10.11.681823

Chromosomal genome assemblies of Antarctic Notothenia coriiceps and temperate relative Paranotothenia angustata

York, J. M.·Bhat, S.·Kim, J.·Cardenas, L.·Cheng, C.- H. C.
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Abstract

Antarctic notothenioid fish genomes contain evidence of an ancient evolutionary history including their remarkable adaptive radiation beginning [~]10 MYA amid extreme selective pressures of Southern Ocean glaciation. Several Antarctic lineages subsequently escaped and recolonized temperate waters, thus their genomes chronicle the re-adaptation to warmer climates. Here, we report two chromosome-scale genomes assembled from HiFi long reads and Hi-C data for the Antarctic cryonotothenioid Notothenia coriiceps and its secondarily temperate close relative Paranotothenia angustata. The N. coriiceps assembly comprises 11 pseudo-chromosomes, spans 1.12 Gbp with a N90 of 81.48 Mbp and 97.8% gene complete with 24,272 annotated genes. The P. angustata assembly comprises 13 pseudo-chromosomes, spans 1.00 Gbp with a N90 of 62.3 Mbp and 97.9% gene complete with 23,828 annotated genes. We report two new N. coriiceps mitochondrial genome structures, map the antifreeze glycoprotein loci, and corroborate the unusual notothenioid ribosomal RNA gene arrangement. The high-quality assemblies of this species pair provide valuable resources for investigating both the historical evolution of polar fish and their adaptive potential to climate change.

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York, J. M., Bhat, S., Kim, J., Cardenas, L., Cheng, C.- H. C.. 2025-10-13. Chromosomal genome assemblies of Antarctic Notothenia coriiceps and temperate relative Paranotothenia angustata. https://doi.org/10.1101/2025.10.11.681823

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